The invention relates to a constant tension suspension device or mechanism for supporting loads, particularly pipes, comprising a main spring system arranged between the suspension portion and the load-bearing portion for receiving the load, and an additional spring system for compensating for variations in tension and compressive forces of the main spring system and for cooperation with a cam element through a roll with the cam element being mounted as an independent swing lever between the additional spring system and the main spring system.
In constant suspension systems used as kinetically compensatory mounting supports for pipes conducting hot fluid, the mechanical elements subjected to the pipe loads accommodate pipe movements created by thermal expansion. The weight of the pipe is kept generally in balance by self-adjustment of the constant suspension system. The sum of existing deviations and additional stress resultant therefrom in the pipe system predominantly remain within an acceptable range.
However, due to external influences or to the direct behavior of the constant suspension system, the pipes or other components may move contrary to expectations, thus not achieving the desired movements as, for example, movement from a cold position to a hot position or vice versa. In special cases, the sum of actual deviations may exceed the acceptable range and, due to such additional secondary tension forces, the life of the constant suspension system, its components and the pipe may be considerably reduced over long periods of use.
Deviations may be due, for instance, to influences in pipe statics which are not always detectable or predictable, to practical variations, such as actual load distribution from the theoretical, to wall thickness tolerances of the pipes (unless they are weighed and weighted prior to installation to compensate for weight differences), to insulating weights which can not be exactly detected/measured in the forward path of movement, to mechanical friction and manufacturing tolerances of the suspension system and its components, and to fatigue of the springs. Moreover, cumulative deviations in long-leg pipe suspension systems of the so-called soft type are very unfavorable. Displacements of the vertical strand may be hindered partly or completely in the expansion leg even in the case of relatively slight deviations. In addition to these types of deviations and damage caused thereby, there are many other potentially dangerous problems, such as water shocks, e.g., caused by an improper descending gradient.
Accordingly, it is possible that the desired movements of the pipes from the cold position to the hot position or vice versa may not be achieved, and for specific/critical points of support, this might not be tolerable.